Adjustable foot mechanism for sash balances



March 18, 1958 w. E. GENCY ADJUSTABLE FOOT MECHAbiISM FOR SASH BALANCESFiled May 1, 1956 2 Sheets-Sheet 1 INVENTOR. WiLLlAM E. GENCY fi/s AMarch 18, 1958 w. E. GE-NCY ADJUSTABLE F OOT MECHANISM FOR SASH BALANCES2 Sheets-Sheet 2 Filed May 1, 1956 INVENTOR. WILLlAM E. GENCY I I I I II 1 1 BY I 2,826,781 ADJUSTABLE FooT MECHANISM FOR SASH BALANCES WilliamE. Gency, Old Greenwich, Conn., assignor to Unique Balance (10., NewYork, N. Y6, a corporation of Illinois Application May 1, 1956, SerialNo. 581,888

Claims. 01. 16-197) This invention relates to mechanisms by means ofwhich the tension of the springs of spiral sash balances may be adjustedand, more particularly, to devices of dow, and the central helicalspring being in cooperative.

relationship with the spiral rod so as to exert its counterbalancingeffect without elongation. Various mechanisms have heretofore beendesigned to permit of adjustment of the tension of the innermost helicalspring in these balances. These previously suggested adjustingmechanisms, however, have been inadequate to satisfy the requirements ofthe trade, either because of themherent diificulty of manipulating themor because the location of the mechanisms has rendered them inaccessibleafter the balances have been installed.

An object of the present invention, accordingly, is to provide amechanism by means of which the spring tension of the inner helicalspring of the spiral sash balances of the above character may be readilyadjusted after the balance has been installed.

Another object of the invention is to provide an adjusting mechanism ofthe above character which may be inexpensively manufactured andconveniently installed.

The foregoing and other objects and advantages are attained by providingan adjusting mechanism that may be incorporated in or carried by thestructure of the foot plate, the mechanism being so formed as to permitof adjustment by the application of a tool such as a screw driverthereto from a position directly beneath the foot plate. Furthermore,the mechanism utilizes a ratchet and pawl connection normally biased toengaging position by a spring which is released by initial axialmovement of the screw driver, prior to the turning movement whicheffects the desired adjustment of the tension of the centrally disposedbalance spring.

In order that the invention may be more readily understood, referencewill now be made to the accompanying drawings, wherein:

Figure 1 is an exploded view of an adjusting mechanism constructed inaccordance with the present invention, this view illustrating thevarious parts in axial alignmm;

Figure 2 is a perspective view of the adjusting mechanism of the:present invention shown with the spiral rod projecting therethrough, asin the operation of the'm'e'chanisrn;

Figure 3a is a view, partly in section, as seen from a point below themechanism looking upwardly, during its assembly;

atent Q "ice Figure 3b is a view similar to Figure 3a showing themechanism after it has been assembled;

Figure 4 is a sectional view taken on a plane indicated by the line 4-4of Figure 5 and looking in the direction of the arrows;

Figure 5 is a sectional view taken on a vertical plane passing throughthe axis of the mechanism; and

Figure 6 is a sectional view taken on a vertical plane indicated by theline 6--6 of Figure 4 and looking in the direction of the arrows,showing how the mechanism permits the adjustment of the central helicalspring.

Referring to Figure 5, there is shown a convention-a1 two-spring spiralsash balance having a top hanger 10 towhich'there is secured the upperend of an outer helical spring 11, the latter being encased in thetubing 12. Within the hanger 10 and the outer spring 11 there is mounteda spiral rod 15 having, at its upper end, a loop 16. An eyelet 17 passesthrough the tubing 12, the hanger 10 and the loop 16, and a screw nailor other fastening device 20 passes through the eyelet 17 and is securedto the window frame 21 as shown, all in accordance with known practice.

In the annular space between the centrally mounted spiral rod 15 and theouter helical spring 11, there is provided an inner helical spring 22mounted on and in frictional engagement with a short section of tubing25 at the upper end of the inner helical spring. The spring 22 issubstantially inextensible axially, but its upper end may be rotated bythe application of a-suificient torque thereto. The tubing 25 has anintegral slotted nut 26 at its upper end, which follows the spiralconfiguration of the rod 15 as the window is raised and lowered andthereby supplies the additional counterbalancing force 'the window israised and lowered, as heretofore explained.

However, the structure described thus far is conventional and thepresent invention, which is directed to a novel mechanism for adjustingthe tension in the'inner helical spring 22, will now be described.

Referring to Figures 1 and 2, the long plate 3650f the foot plate 27 issecured by a rivet 37 to a short plate 49. The plate 40 has an extension41 at one end, forming a pawl plate with a central aperture 55 and twoupstanding diametrically op-posed pawl teeth 58, to be described ingreater detail hereinafter. At the opposite end of the short plate 40, astop 42 is provided, which projects through the opening 45 in the longplate 36 for the purpose to be described hereinafter.

The adjusting member of the mechanism is shown in perspective in Figurel at 46. It is provided, at its lower end, with a flange or plate 47having a slot 50 and an open center sufficiently large to accommodatethe spiral rod i5. Above the flange 47 there is a trunk 43 which has anopen center to accommodate the spiral :rod

15, but a smaller outside diameter than the flange. .As

as that of the lower portion of the adjusting member so as toaccommodate the spinal r0d1'5.

The-long plate 36 is provided, at its upper terminus, I,

with a sleeve 52 which is slightly tapered toward the end and adapted tobe inserted into the lower end of the outer helical spring 11, therebyto hold the spring by friction.

The flange portion 47 of the adjusting member 46 is adapted to seat onthe lower surface of the pawl plate/t1, with the trunk 48 fitting snuglybut rotatably inside the aperture 55. The tubular extension 51, ishoused with a loose fit within the sleeve 52, the extreme upper. end ofthe tubular extension projecting beyond the sleeve, as shown in Figure 2so as to engage frictionally the lower end of the inner helical Spring22 in much the same way that the sleeve 52 engages the outer helicalspring 11.

A ratchet plate or-washer 56 having two oppositely placed notches orrecesses 57 is seated onthe upper surface of the plate 41, the notches57 providing 1ratchet teeth, and the ratchet plate being placed so thatthe notches 57 normally engage the pawl teeth 58 of the plate 41 tomaintain the torsional stress in the inner helical spring .22. Theratchet plate 56 is also provided with two diametrically opposed,inwardly extending teeth 60 projecting into the slot 50 of the adjustingmember 46.

The teeth 60 thereby provide an operative relationship 1 between thepawl plate 41 and the adjusting member 46 so as to maintain the desiredhelical stress in the inner spring 22 which, in turn, helps provide acomponent of the force which supports the window.

A helical spring 61 is seated on the underside of the collar 52 andpresses against the upper surface of the ratchet plate 56 to maintainthe ratchet plate and the pawl plate 41 in operative relationship witheach other. A convenient self-contained sub-assembly consists of theassembled long and short plates 36 and 40, the adjusting member 46, theratchet plate 56 and the spring 61. With the spring 61 and the ratchetplate 56 in position, the teeth 60 being in alignment with the slot 50in the adjusting member 46, and the latter in turn in alignment with therivet head 37 as shown in Figure 3a, the adjusting member 46 isprojected through the opening 55 in the plate, 41, the opening in theratchet plate 56, and the central portion of the spring 61, thencethrough the sleeve 52. After the plate 47 of the adjusting member 46 hascleared the rivet head 37, the adjusting member 46 is turned throughanangle ,of approximately 90 degrees, whereupon the, ratchet plate 56will snap into engagement with the pawl teeth 58 of the pawl plate 41.At this point, however, the slot 50 of the adjusting member 46 will nolonger be in alignment with the rivet head 37 and hence the adjustingmember 46 will not be able to slide downwardly past the rivet 37. Thesub-assembly is then complete. The sub-assembly maybe assembled with thetwo helical springs 11 and 22 as shown and described herein, at thefactory or at the time it is installed on the window.

The adjusting mechanism of the invention, whether it be the sub-assemblyor the complete assembly, is installed on the window by locating theprojecting stop 42 at the corner of the window, as shown in Figure 5,and thereafter bending the lower portion of the long plate 36 through anangle of 90 degrees, hammering the teeth 31 into the bottom of the sashand securing the screws 35 in position in the holes 30.

The adjustment of the tension of the spring 22 is accomplished byinserting the bit of ascrew driver (indicated in phantom in Figure 6)into the slot 50 in the plate 47. If the tension of the spring 22 is tobe increased, then the screwdriver need only be turned in acounterclockwise direction, as viewed from below in Figures 3a and 3b.This will cause the ratchet plate 56 to be moved in a correspondingdirection and the pawl teeth 58 will force the plate upwardly (with thewasher teeth 60riding in the slot 50 to maintain engagement with theadjusting member) to disengage the teeth from the notches 57.3.Continued rotation through 180 degrees will cause the notches 57 to snapinto position with respect to the pawl teeth 58 and thus preventunwinding of the spring. Continued motion of the type above deturnstages of the plate 56. 2O

4 scribed will cause further increase of the tension of the spring.

If the tension of the spring is to be decreased, a screwdriver orsimilar instrument having a bit small enough to fit within the opening55 of the plate 41, but large enough to engage the inwardly-extendingteeth 60 of the ratchet plate 56, is used. The screwdriver is firstmoved axially (upwardly in Figures 1-4, inclusive) to cause the bit toengage the bottom of the teeth 60 and push the plate 56 upwardly untilthe notches 57 disengage the teeth 58. At this instant the tension ofthe spring 22 will tend to cause the plate 56 to move in a clockwisedirection, as viewed from below in Figures 3a and 3b. This motion isresisted to the extent desired by the operator and sufficiently topermit the gradual release of the spring tension. It will be understood,of course, that the pressure of the coil spring 61 will normally permitthis releasing motion to takeplace in half- If continued release oftension is desired, then the screwdriver must be urged upwardly tomaintain the plate 56and its notches 57 out of engagement with the pawlteeth 58.

I claim:

1. An adjusting mechanism for spiral sash balances having a spiral rodand a helical spring with a slotted nut engaging the spiral rod adjacentone end of the spring, comprising a first plate carried by the footplate of said balance, said first plate having a central aperturetherein, an adjusting member rotatably mounted below the first plate,said adjusting member having an open center and an extension with anopen center, said extension passing through the aperture in the firstplate and adapted to engage the helical spring adjacent the end remotefrom said slotted nut, the central opening of said adjusting member andextension being adapted to permit the spiral rod to projecttherethrough, a second plate above the first plate and surrounding theextension of the adjusting member having means to engage saidextensionof the adjusting member, a ratchet and pawl mechanism betweenthe plates, means to maintain said ratchet and pawl mechanism inoperative relationship, and means on said adjusting member to enable itto be turned by a suitableinstrument.

2. A device according to claim 1 wherein the means to maintain saidratchet, and pawl mechanism in operative relationship is a helicalspring surrounding the ad justing member. 1

3. A device according to claim 1 wherein the adjusting member is soformed that the instrument for turning it may, when in operativeposition, disengage the ratchet from the pawl and thereby permit thelowering of the tension in the helical spring.

4. A device according to claim 1 wherein said extension is a tube overwhich the helical spring fits to hold said helical spring.

5. A device according to claim 1 wherein the portion of said adjustingmember below said first plate is a plate having a slot to enable it tobe turned.

6. A device accordingtoclaim 5 wherein the foot plate has a ridge of asize and location such that the ridge normally retains the adjustingmember captive by restricting the axial movement of the adjusting plate,but the adjusting member may be turned to a position where the slot willpass over the ridge and permit the assembling and the disassembling ofthe mechanism.

7. A device according toclaim 5 wherein said adjusting member-engagingmeans comprises a pair of diametrically opposed teeth extending into theslot of the adjusting member, adapted to be contacted from below throughsaid slot by the bit of a screw driver to disengage the ratchet platefrom the pawl teeth and thereby permit the lowering of the tension inthe helical spring.

8. A device according to claim 1 wherein the ratchet mechanism comprisesat least one pawl tooth on the first plate and said second plate is acircular ratchet plate having at least one tooth thereon.

9. A device according to claim plate is formed with at least one theslot of the adjusting means.

10. An adjusting mechanism for two spring spiral sash balances havingthe outer concentric helical spring and the spiral rod secured to thewindow frame and the inner concentric helical spring provided with aslotted nut engaging the spiral rod adjacent one end of the latterspring, comprising a first plate carried by the foot plate of saidbalance, a sleeve carried by said foot plate adapted to hold the lowerend of the outer helical spring, said first plate having a centralaperture therein and two pawl teeth thereon, an adjusting memberrotatably mounted on the first plate and having a slot formed thereinenabling it to be turned, said adjusting member having an open centerand an extension of tubular form passing through the aperture in thefirst plate and through said sleeve and adapted to engage the innerhelical spring 8 wherein the ratchet tooth projecting into adjacent theend remote from the said slotted nut, the central opening of saidadjusting member and extension being adapted to permit the spiral rod toproject therethrough when the window is raised, a ratchet plate abovethe first plate having two notches forming two ratchet teeth adapted toengage said pawl teeth and having a pair of diametrically opposed teethextending into said slot to engage said adjusting member, and a springabove said ratchet plate adapted to engage said ratchet plate andtherebymaintain said ratchet plate in engagement with said first plate.

References Cited in the file of this patent UNITED STATES PATENTS1,926,951 Larson Sept. 12, 1933 2,565,804 De Vries et al. Aug. 28, 19512,602,958 Brown July 15, 1952 2,622,267 Peremi Dec. 23, 1952 2,633,600Larson Apr. 7, 1953

